Synthesis and magnetic properties of Co-Ti-Bi codoped M-type barium ferrite

Journal Article · Fri Apr 01 04:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3556772· OSTI ID:21560147

Lijun, Jia; Huaiwu, Zhang; Shuiming, Yin; Feiming, Bai; Baoyuan, Liu; Qiye, Wen; Jian, Shen ^[1]

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1. State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China)

The effects of Co{sup 2+}, Ti{sup 4+}, and Bi{sup 3+} substitution on the microstructures and properties of low-temperature fired M-type barium hexaferrites have been studied in order to adapt the development of low-temperature cofired ferrites technology and produce gyromagnetic devices with a multilayer process. It is found that Bi{sup 3+} ions can enter into the 2a sublattice and consequently enhance the grain growth and densification due to the activation of the lattice, which in turn first lead to an increase and then a decrease of M{sub s}. The substitution of Bi{sup 3+} ions is beneficial to forming the M phase and lowers the sintering temperature to about 900 deg. C, which is ideal for cofiring with silver paste. Scanning electron microscope and x-ray diffraction analysis have shown that the samples have excellent crystalline grains with a uniform size about 1-2 {mu}m. Moreover, nonmagnetic Ti{sup 4+} ions prefer to enter the 4f{sub VI} octahedral sites, giving rise to the weakening of the strong 12k-4f{sub VI} superexchange path and thus the isotropic exchange energy approaches the other second-order terms on the magnetic Hamiltonian, such as the antisymmetric interaction or even the magnetocrystalline anisotropy. With increasing the substitution content, some Co{sup 2+} ions, which locate in octahedral 12k sites, give a strong planar contribution to the anisotropy. Therefore, M{sub s} and H{sub c} decrease with the Co-Ti-substitution.

• OSTI ID: 21560147
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 7 Vol. 109; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALKALINE EARTH METAL COMPOUNDS
ALLOYS
ANISOTROPY
BARIUM COMPOUNDS
BISMUTH ADDITIONS
BISMUTH ALLOYS
BISMUTH IONS
CERAMICS
CHARGED PARTICLES
COBALT ADDITIONS
COBALT ALLOYS
COBALT IONS
COERCIVE FORCE
COHERENT SCATTERING
DIFFRACTION
ELECTRON MICROSCOPY
FERRIMAGNETIC MATERIALS
FERRITES
GRAIN GROWTH
GRAIN SIZE
INTERACTIONS
IONS
IRON COMPOUNDS
LAYERS
MAGNETIC MATERIALS
MAGNETIC PROPERTIES
MATERIALS
MICROSCOPY
MICROSTRUCTURE
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SCANNING ELECTRON MICROSCOPY
SCATTERING
SIZE
SYNTHESIS
TITANIUM ADDITIONS
TITANIUM ALLOYS
TITANIUM IONS
TRANSITION ELEMENT ALLOYS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION